In 'History of Science and Its Rational Reconstructions', PSA: Proceedings of the Biennial Meeting of the Philosophy of Science Association (1970), Vol. 1970, 91. (Compare Immanuel Kant, Concepts without percepts are empty, percepts without concepts are blind, on Immanuel Kant Quotes web page of this site.

Science itself, no matter whether it is the search for truth or merely the need to gain control over the external world, to alleviate suffering, or to prolong life, is ultimately a matter of feeling, or rather, of desirethe desire to know or the desire to realize.

In science it often happens that scientists say, 'You know that's a really good argument; my position is mistaken,' and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion.
(1987) -- Carl Sagan